DE69324650T2 - Mixing method for a digital video tape recorder - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the invention

The present invention relates to a digital video cassette recorder (VCR) and, more particularly, to an interleaving/de-interleaving arrangement and method for a digital VCR which can effectively correct errors occurring during recording or playback of compressed data and improve error correction capability, particularly during variable speed playback.

2. Description of the state of the art

The errors that occur during recording and playback in a digital VCR can be classified as random errors and burst errors. Random errors occur independently in digital signal lines due to additive noise during signal processing, and a burst error is a successive error that occurs with respect to a bit stream of transmission data under the influence of the tape condition, etc. A burst error can be corrected by replacing it with random errors by an interleaving/deinterleaving process.

A conventional interleaving device for a digital VCR as shown in Fig. 1 comprises an outer encoder 1 for performing outer coding on a compressed input data stream and for successively outputting the data stream with an outer code symbol added thereto, a first sector field memory 2 for successively storing the data output from the outer encoder 1, and an inner encoder 3 for reading the data stored in the first sector field memory 2 in an order different from that of storing the data in the first sector field memory 2, for performing of inner coding, outputting and recording the data having an inner code symbol added thereto on a tape via a head. The interleaving device is also provided with an inner decoder 4 for decoding only data having the inner code symbol among the data reproduced from the tape, detecting errors in the data and performing interleaving with respect to these detected errors, a second sector field memory 5 for distributively storing the interleaved data from the inner decoder 4, and an outer decoder 6 for reading out data from the second sector field memory 5 in an order different from that of writing the data and performing decoding with respect to data having the outer code symbol to correct the errors.

In the conventional interleaving arrangement constructed as above, when the compressed data stream as shown in Fig. 2A is input, the outer encoder 1 performs outer coding in a vertical direction with respect to a series of symbols of the input data as shown in Fig. 2B and outputs data having the outer code symbol. Then, redundancy is added to the data having the outer code symbol as shown in Fig. 2C, and the data with added redundancy is stored in the first sector array memory 2 in the order shown in Fig. 2D.

The inner encoder 3 reads the data from the first sector array memory 2 in an order different from that in which the data was stored, and performs interleaving to add the inner code symbol to the data. Accordingly, the order of the data is changed to be different from that of the input data, causing a burst error to be replaced by random errors. The data stream interleaved as described above is then inner-encoded by the inner encoder 3, with the result that strong error correction coding (ECC) is performed.

The inner decoder 4 decodes the data having the inner code symbol among the data having the inner and outer code symbols reproduced from the tape, and detects and corrects the errors. That is, in correcting the errors, the inner decoder 4 performs interleaving with respect to the errors existing beyond its capabilities, and distributively stores the interleaved data still having errors in the second sector array memory 5. The outer decoder 6 performs outer decoding with respect to the data stored in the second sector array memory 5 to correct the remaining errors, and thereby various kinds of errors occurring during reproduction in a digital VDR can be corrected and prevented.

The conventional arrangement as described above thus offers a great possibility of correcting various errors that occur during data reproduction and is suitable for use in a digital VCR for professional purposes.

However, in a household digital VCR, such a complex arrangement for strong error correction cannot be used because of a limitation of the recording frequency bandwidth and the high cost.

In addition, in high speed playback, for example, in a picture search mode, the VCR head as shown in Figs. 4A to 4C passes over several tape tracks, and the head scanning track area in one track as well as the size of a sector array memory in the conventional arrangement is inversely proportional to the degree of high speed.

Practically, the VCR head in high speed playback has a non-linear scanning track as shown in Fig. 4C, and this results in the maximum interleaving area for ECC being further limited as compared with the linear head scanning track. In addition, in high speed playback, the head continuously passes the track part of the same position due to the limited interleaving area, and the image data of the same image part is extracted. Accordingly, in order to obtain the image data of the other image parts, data mapping for rearranging the data recording position is required.

Further, when a signal is recorded on a tape track by the conventional arrangement as shown in Fig. 10A, redundancy is added to the signal by using a two-dimensional Reed-Solomon code for correcting mismatches. various types of burst and random errors. Therefore, during normal reproduction of the signal, the decoding field is completely occupied by information data, and the two-dimensional Reed-Solomon decoding can be carried out.

However, in special reproduction such as high speed playback, only a part of the track can be sampled and therefore the decoding field with information data is partially occupied and only one-dimensional error decoding can be used, with the result that the confidence in the correction of errors is deteriorated.

The data segments reproduced by the conventional arrangement are classified into complete segments and incomplete segments, and the data segment is made up of slices which are the variable unit in which the image data and other information are compressed and condensed. Accordingly, as shown in Fig. 15, a plurality of slices may exist in the K-th segment, while one slice may exist across two segments as shown in the (k+1)-th segment.

These slices may be implemented with variable length coding (VLC) or compressed at different rates when encoding a high quality picture or a normal picture. Thus, the lengths of the respective compressed data streams may appear different from each other even though the same bit information of the same amount is compressed. Accordingly, to perfectly implement variable length decoding (VLD) in a decoder, a complete bit stream should be reproduced in one slice unit.

However, in the conventional arrangement, groups of complete or incomplete segments are placed in the detected area as shown in Fig. 16 when the reproduced data stream has been deinterleaved in variable speed playback. If the slices constituting the unit of data compression exist over incomplete segments excluding the groups of complete segments, the disks in the incomplete segments will be of no use, resulting in data loss.

EP-A-0 508 602 describes a video-audio digital recording device comprising an analog-to-digital converter for converting analog data into digital data when data is recorded on a cassette tape; an interleaver RAM for storing a blocked video signal in a unit of a block; a high efficiency encoding circuit for compressing the video signal read out from the interleaver RAM and for carrying out the process of reading the video signal from the interleaver RAM; and a video error collection encoder for encoding the compressed video signal output from the high efficiency encoding circuit for error correction. For placing data recorded on a cassette tape, the device comprises de-interleaver elements operating with the opposite effect. The interleaving RAM interleaves a digital video signal of one block having a plurality of pixels output from the audio-video converter only once in a block unit. The process of interleaving/de-interleaving the compressed data is carried out regardless of the regional space.

SUMMARY OF THE INVENTION

It is an object of the present invention to provide an interleaving/de-interleaving device for a digital VCR and the method therefor, which can effectively correct various kinds of burst and random errors in recording/reproducing compressed data.

It is another object of the present invention to provide an interleaving/de-interleaving device for a digital VCR and the method therefor, which make it possible to effect maximum interleaving/de-interleaving within a predetermined high speed by determining an interleaving/de-interleaving area according to the predetermined high speed and by carrying out the interleaving/de-interleaving within the determined interleaving/de-interleaving area.

To achieve the above objects, there is provided an interleaving/deinterleaving arrangement for a digital VCR according to the independent claims. Preferred embodiments of the invention are claimed in the dependent claims.

Briefly, the arrangement comprises an interleaving/deinterleaving control means for restrictively determining an interleaving/deinterleaving area according to a predetermined maximum speed in recording/reproducing compressed image data;

a storage device for storing and reading out the compressed image data in a particular format under the control of the interleaving/deinterleaving control device; and

means for performing interleaving/de-interleaving with respect to the compressed image data supplied from the storage means.

Furthermore, to achieve the above objects, an interleaving/deinterleaving method for a digital VCR according to the independent method claims is provided. The method includes the steps of:

Dividing a compressed input data stream into a synchronization signal and into data and formatting the data in the segment unit;

Reading the formatted data segments in a zigzag pattern and storing the read data segments in a memory image;

Dividing each of the data segments stored in the memory map into n segment blocks and successively writing the segment blocks in a data field while shifting each of the segment blocks for a vertical size of the data segment; and

Performing intersymbol interleaving with respect to data symbols in the segment blocks by classifying the data symbols and dividing the classified data symbols in a row.

BRIEF DESCRIPTION OF THE DRAWINGS

The above objects and other advantages of the present invention will become apparent by describing the preferred embodiments thereof with reference to the accompanying drawings, in which:

Fig. 1 is a block diagram of the conventional interleaving arrangement for a digital VCR;

Figs. 2A to 2D are views explaining the interleaving operation by the arrangement of Fig. 1;

Fig. 3 is a block diagram of an embodiment of the interleaving/deinterleaving arrangement according to the present invention;

Figs. 4A to 4C show the states of the head scanning track on a tape, the track contact area and a non-linear track scanning track in a high-speed search mode;

Figs. 5A to 5C are views explaining the interleaving operation using the arrangement of Fig. 3;

Fig. 6 is a block diagram of another embodiment of the interleaving/de-interleaving arrangement according to the present invention;

Figs. 7A to 7C show the states of a recording data format of a digital VCR, an interleaving process and interleaved data;

Fig. 8 is a block diagram of yet another embodiment of the interleaving arrangement according to the present invention;

Fig. 9 is a block diagram of yet another embodiment of the deinterleaving arrangement according to the present invention;

Fig. 10A shows the state of a tape track being scanned during normal playback;

Fig. 10B is a view explaining a decoding field entirely occupied by information data;

Fig. 10C shows the state of a tape track being scanned during variable speed playback;

Fig. 10D is a view explaining a decoding field partially occupied by information data;

Fig. 11 is a view explaining a data formatting process in recording according to the present invention;

Fig. 12 illustrates the state of channel division resulting from the zigzag scanning of the compressed data in the data formatting process of Fig. 12;

Fig. 13 is a block diagram of yet another embodiment of the interleaving arrangement according to the present invention;

Fig. 14 is a block diagram of yet another embodiment of the deinterleaving arrangement according to the present invention;

Fig. 15 is a view explaining the structure of a slice existing in the compressed data;

Fig. 16 shows an example of groups of complete and incomplete segments in a detected area;

Figs. 17A to 17E are views explaining a data formatting process in the recording/reproducing of data according to the present invention;

Fig. 18 is a view explaining a synchronizing signal and data which are divided from the compressed data stream by the arrangement of Fig. 13;

Figures 19A and 19B show the data formats arranged in interleaving and deinterleaving according to the present invention;

Figures 20A and 20B show the data formats rearranged in interleaving and deinterleaving according to the conventional arrangement; and

Fig. 21 is an algorithm diagram incorporating the interleaving-de-interleaving method according to the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Fig. 3 shows an embodiment of the interleaving/deinterleaving arrangement for a digital VCR according to the present invention. The arrangement comprises a source encoder 10 for encoding an input bit data stream, a memory mapper 20 for storing and reading out the image data stream encoded by the source encoder 10 in the segment unit, an interleaving control unit 30 for limiting an interleaving area according to header information in a line at a predetermined maximum speed, an intersegment interleaver 40 for performing intersegment interleaving with respect to segments of the image data stream supplied from the memory mapper 20, an outer encoder 50 for performing outer encoding with respect to the image data stream from the intersegment interleaver 40, an intrasegment interleaver 60 for performing intrasegment interleaving with respect to the segments of the image data stream from the outer encoder 50 and an inner encoder 70 for performing inner encoding with respect to the image data stream from the intrasegment interleaver 60.

A video head can pass through many more tracks, as shown in Fig. 4A, in high speed playback, such as in the picture search mode. than in normal speed playback as shown in Fig. 4B, and therefore substantially much data in the track cannot be read out. Accordingly, errors occur and propagate due to the unread data, so that even an efficient ECC cannot function. The maximum interleaving area should therefore be smaller than the area of the track scanning track covered by the head in the maximum speed mode of the VCR, which area is obtained by the following expression

where S (0 ≤ S ≤ 1) is an interleaving area, N is the maximum speed in reproduction, and TD (0 ≤ TD ≤ 1) is a tracking deviation degree.

In this embodiment, after the source encoder 10 has encoded an input digital data stream and supplied the data stream as shown in Fig. 5A, the memory mapper 20 divides the data stream in the segment unit as shown in Fig. 5B and stores the divided data stream. At this time, the interleave control unit 30 supplies the memory mapper 20 with a control signal for determining an interleave area according to a VCR status signal and ID information in a line with the above expression and for executing interleave within the determined area, thereby preventing the reduction of the interleave effect in normal and high speed reproduction.

At this point, TD indicates a tracking degree of the head. When TD = 1, the center of the head coincides with that of the track, and thus scanning is completed. When TD < 1, the track deviates from the head. That is, in variable speed playback, the head passes many tracks, so the area in which a head can read information data for one track should be in the range of 0 ≤ TD ≤ 1.

The intersegment interleaver 40 performs intersegment interleaving and supplies the interleaved data to the outer encoder 50, where the intersegment interleaving can be achieved by interleaving data between segments in the process of reading data from the memory map 20 in the segment unit. The outer encoder 50 performs the outer encoding on the data from the intersegment interleaver 40 and supplies the encoded data to the intrasegment interleaver 60. The intrasegment interleaver 60 performs intrasegment interleaving, i.e., it interleaves data within segments, as shown in Fig. 5C. Burst errors in the data stream can thus be replaced by random errors, and the data from the intrasegment interleaver 60 can be EEC processed by the encoder 70 and then written to the tape by the head.

As shown in Fig. 6, the interleaving/deinterleaving arrangement for a digital VCR according to another embodiment of the invention comprises a formatter 100 for determining the recording format with respect to an input digital data stream according to ID information and overhead information, a memory mapper and decoder 200 for maintaining continuity between segments and performing interleaving with respect to the output of the formatter 10 according to the characteristics of the VCR and for dividing the data stream, a buffer section 300 for buffering the output signals from the memory mapper and decoder 200, a delay section 400 for successively delaying the data buffered by the buffer section 300 for a predetermined time, an encoder 500 for encoding the data delayed by the delay section 400, a Intersymbol interleaver 600 for performing intersymbol interleaving on the output of the encoder 500, an inner encoder 700 for performing inner encoding on the interleaved data from the intersymbol interleaver 600, a channel encoder 800 for connecting the data stream to a tape channel, and a channel decoder 900 for decoding the reproduced data from the tape.

In the above embodiment, the formatter 100 receives a digital data stream, sets the VCR recording format in terms of data segment lines (compressed ized data or error correction (ECC) except for the preceding header as shown in Fig. 7A and then supplies the formatted data stream to the memory mapper and decoder 200. The memory mapper and decoder 200 effects interleaving on the supplied data stream according to the characteristics of the VCR while maintaining continuity between segments. The interleaved data passes through buffers B1 to Bn in the buffer section 300 and through delay circuits D1 to Dn in the delay section 400 and is then constructed as shown in Fig. 7B.

When the interleaved data is encoded by the encoder 500 and applied to the intersymbol interleaver 600, the data is completely rearranged as shown in Fig. 7C and is inner-encoded by the inner encoder 700 so as to be supplied to the channel encoder 800. The channel encoder 800 records the data supplied from the inner encoder 700 onto the tape by connecting the channel of the data stream to that of the tape, thereby completing the interleaving process.

When the data recorded on the tape is to be reproduced, the channel decoder 900 decodes the reproduced data and detects and corrects the errors. Then, the acquired data is reversely processed by the aforementioned interleaving process, i.e., it is subjected to a deinterleaving process.

In variable speed playback, in reproduction, the interlace area is determined according to the predetermined maximum speed. The segments in the adjacent areas within the determined area are successively formatted as shown in Figs. 7A, 7B and 7C. Accordingly, no discontinuity occurs between the segments and thus the interlace effect is not reduced at any speed lower than the maximum speed, although the head of the VCR may have non-linear scanning tracks.

Fig. 8 shows yet another embodiment of the interleaving arrangement according to the present invention. The arrangement has a format divider 101 for dividing an input stream of compressed data into a synchronizing signal and data and for formatting the synchronizing signal and the data resulting from the division, a memory mapper 102 for reading and storing data segments of the divided data in a zigzag form, an outer encoder 103 for performing outer coding (i.e., Reed-Solomon coding) on the data N1 and K1 stored in the memory mapper 102 and for supplying the data to which an outer code symbol is added, a demultiplexer 104 for demultiplexing the segments supplied from the outer encoder 103 and temporarily storing the data segments in n buffers 105 arranged in a vertical direction, a multiplexer 106 for multiplexing the data segments from the buffers 105 so that the multiplexed data is supplied, an inner encoder 107 for performing inner coding on the data from the multiplexer 106 and for supplying the data to which an inner code symbol has been added, an intersymbol interleaver 108 for performing intersymbol interleaving with respect to the data supplied from the inner encoder 107, a synchronizing and header signal generator 110 for receiving the synchronizing signal from the format divider 101 and for supplying a header signal corresponding to the synchronizing signal together with the synchronizing signal, a system control unit 109 for controlling the format divider 101 and the synchronizing and header signal generator 110 according to an input TBM signal, a formatter 111 for formatting the synchronizing and header signals from the synchronizing and header signal generator 110 and the symbol code data from the intersymbol interleaver 108, a channel modulator 112 for modulating the data from the formatter 111 and supplying the modulated signal as a tape recording signal and a recording amplifier 113 for amplifying the data from the channel modulator 112 to cause the data to have an appropriate value and for recording the amplified data on the tape.

For the reproduced data, the deinterleaving process is carried out by the deinterleaving arrangement in which the above interleaving arrangement is constructed reversely as in Fig. 9, and therefore the description thereof is omitted.

It will be appreciated that the data divided by the format divider 101 enters in two directions so that it is divided into two channels, and therefore the description will be given for only one channel below.

The format divider 101 receives a stream of compressed data and divides the data stream into a synchronizing signal and compressed data as shown in Fig. 11A and then performs formatting. The divided data is scanned in a zigzag form and stored in the segment unit in the memory map 102 as shown in Fig. 11B, being divided into channel data A and channel data B as shown in Fig. 11C to be processed separately when the data is read out therefrom.

Multiplexers 106 and 126 multiplex the interleaved data and supply the multiplexed data. The inner encoders 107 and 127 add the Reed-Solomon code of (N2, K2) to the data from the multiplexers 106 and 126 and perform the inner coding as shown in Fig. 11G, so as to supply the encoded data to the intersymbol interleavers 108 and 128. The intersymbol interleavers 108 and 128 perform intersymbol interleaving on the symbol data, thereby correcting the random errors.

Thus, from the synchronizing and header signal generator 110, the formatters 111 and 131 receive a synchronizing signal in divided form from the format divider 101 and a header signal corresponding to the synchronizing signal under the control of the system controller 109 and perform formatting on the received data together with the data from the intersymbol interleavers 108 and 128 as shown in Fig. 11H so as to supply the formatted data to the channel modulators 112 and 132. The channel modulators 112 and 132 perform channel modulation on the supplied data. The modulated data is supplied to the recording amplifiers 113 and 133 to be amplified and is then recorded on the tape.

During playback, errors can be prevented by reversing the data formatted and recorded as described above using the circuit in Fig. 9.

Fig. 13 shows yet another embodiment of the nesting arrangement according to the present invention. The arrangement has a format divider 101 for dividing len an input stream of compressed data into a synchronizing signal and data and for formatting the synchronizing signal and the data resulting from the division, a memory mapper 102 for reading out and storing the data divided by the format divider 101 in a zigzag form, a demultiplexer 104 for dividing the data into a segment stored in the memory mapper 102 into n blocks and for demultiplexing each segment block and storing the demultiplexed data segment in n buffers 105, a multiplexer 106 for multiplexing the data temporarily stored in a buffer 105, an intersymbol interleaver 108 for performing interleaving with respect to the symbol data multiplexed by the multiplexer 106 to divide the symbol data along the same line per block, a synchronizing and header signal generator 110 for receiving the synchronizing signal from the format divider 101 and for supplying a header signal corresponding to the synchronizing signal together with the synchronizing signal, a system controller 109 for controlling the format divider 104 and the synchronizing and header signal generator 110 according to a TBM input signal, a formatter 111 for formatting the synchronizing and header signals from the synchronizing and header signal generator 110 and the symbol data from the intersymbol interleaver 108, a channel modulator 112 for modulating the data from the formatter 111 to make the modulated data suitable for recording on the tape, and a recording amplifier 113 for amplifying the data from the channel modulator 112 to an appropriate value and recording the amplified data on the tape.

It is clear that the data divided by the format divider 101 enters in two directions so that the data is divided into two channels, therefore the description will follow for only one channel.

Moreover, the deinterleaving arrangement corresponding to the interleaving arrangement as shown in Fig. 14 and the structure and operation thereof are simply reverse to the interleaving arrangement and therefore will not be described.

The format divider 101 divides an input stream of compressed data into a synchronizing signal and compressed data and performs formatting as shown in Fig. 18, thus arranging the compressed data successively per The data resulting from the division into a synchronizing signal and data is successively written into the memory maps 102 in a zigzag form in the segment unit as shown in Fig. 17A.

The demultiplexer 104 demultiplexes the data stored in the memory map 102 so as to divide one segment into N blocks as shown in Fig. 7B, and writes the segments for each block into the buffer section 105 containing N buffers. That is, one segment is written into the buffer 1, and the next segment is shifted for a vertical size so as to be written into the buffer 2 as shown in Fig. 17C.

The multiplexer 106 multiplexes the vertically written data and then transfers to the intersymbol interleaver 108 symbols for blocks in the segments. The intersymbol interleaver 108 interleaves to form n blocks by copying the data in the same position as shown in Fig. 17D, i.e., classifies the data according to the line. The interleaving process for classifying the data is as shown in Fig. 19A, whereas the conventional process is as shown in Fig. 20A.

Thus, from the synchronizing and head signal generator 110, the formatter 111 receives a divided synchronizing signal from the format divider 101 and a head signal corresponding to the synchronizing signal under the control of the system controller 109 and performs formatting on the received data together with the data from the intersymbol interleaver 108 as shown in Fig. 17E so as to supply the formatted data to the channel modulator 112. The channel modulator 112 performs channel modulation on the supplied data. The modulated data enters the recording amplifiers 113 to be amplified and is then recorded on the tape.

In the conventional method, after the deinterleaving process is completed by performing reverse interleaving by means of the arrangement of Fig. 14, the incomplete segment should be removed as shown in Fig. 20B. However, according to the present invention, as shown in Fig. 19B, the incomplete segment becomes longer and the orders of the data between The distances between adjacent segments are changed, thereby connecting the blocks between incomplete segments and increasing the probability of having a slice lying in two segments. Accordingly, the slices extracted from the segments can be detected even better, thereby improving the image quality.

The process of removing slices from incomplete segments to make them usable is explained with reference to Fig. 21.

First, after interleaving/de-interleaving is performed, it is determined whether a recorded/reproduced data segment is complete or incomplete. If it is determined that the data segment is complete, normal data processing is carried out with respect to the complete data segment, which ends when the last segment is processed. If it is determined that the data segment is incomplete, a segment header signal and the end point DSEP and the start point DSSP of the incomplete data are detected.

If the start point of the data stream does not exist, the size of the start point of a slice a is compared with that of the end point of the data stream. At this point, if the start point of the slice has a smaller size, an appropriate process is executed, which ends when the last data segment is processed. If the size of the start point of the slice is not smaller, it is determined whether the data segment is the last one and the process ends at this point, which means that no slice is taken.

If the start point of the incomplete data stream exists, the size of the start point of the slice is compared with that of the data stream. At this point, if the size of the start point of the slice is larger, a corresponding process is executed until the last data segment is processed. When the last data segment comes out, the process ends and the start point of the slice which is not larger is removed. As a result, the slice taken out from the incomplete data segment can be used for improved image quality.

From the foregoing, it can be seen that according to the present invention, interleaving/de-interleaving is performed within an interleaving area limited according to a predetermined maximum speed in variable speed playback, so that the error correction ability is improved even though the VCR head may have a non-linear scanning track. The error correction ability may also be better when the error decoding field has insufficient data in high speed playback. Moreover, many disks can easily get into an incomplete data segment, thereby providing high resolution picture quality.

Claims (15)

1. An interleaving/deinterleaving arrangement for a digital video cassette recorder, comprising: an interleaving/de-interleaving control means (30) for determining a restrictive interleaving/de-interleaving area smaller than the area covering a track having a maximum speed in recording and reproducing compressed image data; a storage device (20) for storing and reading out the compressed image data in a unit of a segment under the control of the interleaving/deinterleaving control device; and means (40, 60) for performing inter-segment and intra-segment interleaving/de-interleaving with respect to the compressed image data supplied from the storage means; said device performing the interleaving function during recording of compressed image data and the deinterleaving function during playback of recorded compressed image data, wherein the deinterleaving is performed in the opposite way to the interleaving and wherein the deinterleaving part of the device is connected in reverse sequence to the interleaving part of the device. 2. An interleaving/de-interleaving arrangement for a digital video cassette recorder according to claim 1, comprising: - for the nesting function - a source encoder (10) for encoding an input image data stream; wherein the interleaving control unit (30) provides a control signal for limiting the interleaving area according to header information in line with the predetermined maximum speed; wherein the memory mapper (20) in the segment unit stores and reads out the image data stream encoded by the source encoder according to the control signal from the interleaving control device (30); wherein the intersegment interleaver (40) performs intersegment interleaving with respect to segments of the image data stream provided from the memory mapper (20); and wherein the intra-segment interleaver (60) performs intra-segment interleaving with respect to the segments of the image data stream from the inter-segment interleaver (40); and wherein - for the de-nesting function - corresponding elements are operated to the opposite goal and are connected in the reverse sequence. 3. An interleaving/de-interleaving device according to claim 2, wherein the interleaving area restrictively determined by the interleaving control unit (30) is obtained by the following expression where S is an interleaving area, N is the maximum speed, and TD is a track deviation degree. 4. An interleaving/de-interleaving device according to claim 2, further comprising: an outer encoder (50) connected between the intersegment interleaver (40) and the intrasegment interleaver (60) for performing outer encoding on the image data stream from the intersegment interleaver (40); and an inner encoder (70) for performing inner encoding on the image data stream from the intrasegment interleaver (60) and for supplying the inner encoded image data stream as a tape recording signal. 5. Interleaving/deinterleaving arrangement for a digital video cassette recorder, comprising: - for the nesting function - a formatter (100) for dividing an input image data stream into a synchronization signal and image data; a memory mapper (200) for storing and reading the image data stream from the formatter (100) according to identification information for each data segment of the image data; a decoder (200) for decoding the image data stream from the storage device (200) according to the identification information of the data segment and for providing the decoded image data stream; a buffer and delay device (300, 400) for performing the interleaving, maintaining the continuity between the data segments by buffering the image data stream from the decoder (200) and for successively delaying the buffered image data stream for a predetermined time; a first encoder (500) for encoding the output signal of the buffer and delay device (300, 400) and for providing the successively delayed image data stream; an intersymbol interleaver (600) for performing intersymbol interleaving with respect to the interleaved data segment from the first encoder (500); a second encoder (700) for adding the identification information of the data segment and overhead information to the synchronization signal from the formatter (100); and a channel encoder (800) for receiving the output signals of the intersymbol interleaver (600) and the second encoder (700) for reconstructing a complete data segment and for channel modulating the reconstructed data segment to provide the channel modulated data segment as a tape recording signal; and wherein - for the de-nesting function - corresponding elements are operated for the opposite purpose and are connected to each other in the reverse sense (22). 6. An interleaving/de-interleaving device according to claim 5, further comprising: an inner decoder (700) connected between the intersymbol interleaver (600) and the channel encoder (800) for performing inner coding with respect to the image data interleaved by the intersymbol interleaver (600). 7. Interleaving/de-interleaving arrangement for a digital video cassette recorder, comprising: - for the nesting function - a format splitter (101) for splitting a compressed input data stream into a synchronization signal and data and for formatting the split synchronization signal and data; a memory mapper (102, 112) for reading and storing data segments of the divided data in a zigzag shape; a demultiplexer (104, 124) for demultiplexing the data segments provided by the memory mapper (102, 122) and for temporarily storing the data segments in a plurality of buffers (105, 125); a multiplexer (106, 126) for multiplexing the data segments from the buffers (105, 125) and for providing the multiplexed data; an intersymbol interleaver (108, 128) for performing intersymbol interleaving with respect to the data provided by the multiplexer (106, 126); a synchronization and head signal generator (110) for receiving the synchronization signal from the format divider (101) and for supplying a head signal corresponding to the synchronization signal together with the synchronization signal; a system control unit (109) for controlling the format divider (101) and the synchronizing and head signal generator (110) according to an input TBM signal; a formatter (111, 131) for formatting the synchronization and header signals from the synchronization and header signal generator (110) and the symbol data from the intersymbol interleaver (108, 128); and a channel modulator (112, 132) for modulating the data from the formatter (111, 131) and providing the modulated data as a tape recording signal; and wherein - for the de-nesting function - corresponding elements are operated for the opposite purpose and are connected in the reverse sequence. 8. An interleaving/de-interleaving arrangement according to claim 7, further comprising: an outer encoder (103, 123) connected between the memory maps (102, 122) and the demultiplexer (104, 124) for performing outer coding on the data from the memory map (102, 122) and for supplying the data with an outer code added thereto; and an inner coder (107, 127) connected between the multiplexer (106, 126) and the intersymbol interleaver (108, 128) for encoding the data from the multiplexer (106, 126) and for supplying the data by adding an inner code to it. 9. An interleaving/de-interleaving arrangement according to claim 7, wherein the format divider (101) selects the data per symbol or per block and divides the selected data into a plurality of data channels. 10. An interleaving/de-interleaving arrangement according to claim 7, wherein the format divider (101) samples the data per line in a zigzag manner and divides the sampled data into a plurality of data channels. 11. An interleaving/de-interleaving device according to claim 7, wherein the demultiplexer (106, 126) performs a line shift with respect to the data segments so that each data segment has delay times which are different from each other, and stores the shifted data segments in the plurality of buffers (105, 125), whereby an interleaving effect is not degraded in a variable speed playback. 12. An interleaving/deinterleaving method for a digital video cassette recorder, comprising the steps: - for the nesting function of the procedure - Dividing a compressed input data stream into a synchronization signal and into data and formatting the data in the segment unit; Reading the formatted data segments in a zigzag pattern and storing the read data segments in a memory image; Dividing each of the data segments stored in the memory map into n segment blocks and successively and vertically writing the segment blocks in a data field while shifting each of the segment blocks for a vertical size of the data segment; and performing intersymbol interleaving with respect to data symbols in the segment blocks by classifying the data symbols and dividing the classified data symbols in a row; and - for the deinterleaving function of the procedure - Perform corresponding steps of opposite effect in a reverse sequence. 13. The interleaving/de-interleaving method of claim 12, wherein the formatting step includes the substep of dividing the data segments into a plurality of data channels. 14. The interleaving/de-interleaving method according to claim 12, wherein in said dividing and shifting step, said data segments are each divided into a plurality of blocks, thereby preventing a small burst error in said data segment. 15. An interleaving/deinterleaving method for a digital video cassette recorder, comprising the steps: - for the nesting function of the procedure - Determine whether a recorded/played data segment is complete or incomplete; Performing normal data processing when the detected data segment is complete and ending with the last data segment; detecting a segment header signal and start and end points of the stream of incomplete data if the detected data segment is incomplete, and checking whether the start point of the stream of incomplete data exists; Comparing the size of the start point of a slice and the end point of the data stream if the start point of the data stream does not exist; extracting the slice from the incomplete data segment if the start point of the slice is smaller than the end point of the data stream, and performing the data segment capture step if the start point of the slice is not smaller; comparing the size of the start point of the slice and the start point of the data stream if the end point of the data stream exists in the slice extraction step; and extracting the slice from the incomplete data segment if the start point of the slice is greater than the start point of the data stream, and performing the segment capture step if the start point of the slice is not greater; and - for the deinterleaving function of the procedure - Perform corresponding steps of opposite effect in a reverse sequence.